1. Field of the Invention
The present invention relates to a woven slide fastener stringer bound on a fastener tape by weaving a continuous element row of synthetic resin monofilament into the fastener tape woven at the same time, along one longitudinal edge thereof.
2. Description of the Related Art
According to a well known woven slide fastener stringer of this kind, as disclosed in, for example, Japanese Patent Publication No. 2-17162, element rows constituted of a plurality of coil-like parallel coupling element portions of synthetic resin monofilament are bound on a fastener tape woven at the same time along one longitudinal edge of the same tape with binding warp yarns and foundation weft yarns.
Each of the coupling element portions comprises a coupling head protruded outward from the longitudinal edge of the fastener tape, upper and lower leg portions extending in parallel inward of the same tape, and a connecting portion for connecting upper and lower leg portions of adjacent coupling element portions. In the slide fastener stringer disclosed in the same publication, foundation weft yarns composed of two-folded yarns by double picks are disposed below the aforementioned lower leg portion of each coupling element portion. That is, every time the weft yarn is inserted, a single coupling element portion is woven in with the same weft yarn.
As shown in FIG. 3 (representation of the coupling head of the coupling element portion is omitted as required to facilitate illustration in the figure), the Publication discloses that the coupling element portion E is supported by 12 binding warp yarns W1 to W12 in total. On the connecting portion side of the coupling element portion E, eight warp yarns W5 to W12 are guided by repeating a unit of high-high-medium-low in succession in plan view of the fastener tape. On the coupling head side, four warp yarns W1 to W4 are guided by repeating the order of high-medium-low-medium. Here, xe2x80x9chighxe2x80x9d means that the warp yarn supports the upper and lower leg portions L from above, xe2x80x9cmediumxe2x80x9d means that the warp yarn is disposed between the lower leg portion and a foundation weft yarn w, and xe2x80x9clowxe2x80x9d means that warp yarn support the foundation weft yarn w and the upper and lower leg portions L from below. Meanwhile, in FIG. 3, representation of the coupling head of the coupling element portion is omitted as requried to facilitate illustration.
Such a weaving structure not only stabilizes a pitch between adjacent coupling element portions but also intensifies the density of the warp yarns constituting a warp yarn pocket without providing a particularly high tension. As a result, the pitch between the coupling element portions is stabilized so that an excellent plasticity and flexibility of the fastener tape can be secured. Thus, the slide fastener can be sewn to an attachment material such as clothes or a bag at a high speed.
However, with respect to the slide fastener stringer disclosed in the above publication, particularly to a manner of mingling of the binding warp yarns with respect to the foundation weft yarn for fixing the parallel coupling element portions, each of the fixing warp yarns is guided by repeating the unit of high-high-medium-low or the unit of high-medium-low-medium as described above. Thus, in either case with respect to the foundation weft yarn w, as shown in FIG. 3, the binding warp yarn runs over three weft yarns w composed of two-folder yarns and then runs below the weft yarn w of next position, and this sequence is repeated.
Usually, upon manufacturing a finally finished slide fastener, with the coupling element row bound on a longitudinal edge of each of two slide fastener stringers engaging each other, a desired number of the coupling element portions are cut out at an interval corresponding to the length of a slide fastener in the longitudinal direction thereof so as to form a so-called space portion to complete the fastener chain. When the coupling element portion is cut out, the coupling head is cut out by cutting a border between the coupling head and the upper and lower leg portions, and after that, the upper and lower leg portions of each coupling element portion is pulled out from a warp yarn pocket. Therefore, when the space portion is formed, the binding warp yarn supporting each coupling element portion from above or below floats, i.e., moves easily in the upward and downward directions, in a region in which the space portion is formed.
On the other hand, since a process for attaching top and bottom end stops, a process for installing the slider and the like are provided after the formation of the space portion for manufacturing the slide fastener, if the binding warp yarn floats too largely, i.e., moves easily too far in the upward direction or the downward direction, due to the formation of the space portion, the binding warp yarns hinder subsequent processes, thereby causing various troubles. Further, the fastener chain is cut at the center of the space portion in the longitudinal direction so as to produce a final slide fastener. The binding warp yarn floating in the space portion as describe above leaves the fastener tape while an end thereof is fixed, because it is little supported by the foundation weft yarn. As a result, the commercial value of the produced slide fastener is lowered or additional work is needed for treating that trouble.
In the slide fastener stringer disclosed in the foregoing publication, the binding warp yarn runs over three weft yarns composed of two-folded yarns with respect to the foundation weft yarn and then is guided below the weft yarns of a next position. As a result, the binding warp yarn floats over a length corresponding to the three coupling element portions, and therefore, in a process after the space portion is formed, the binding warp yarn may be caught or cut out, or an end portion of the coupling element portion adjacent to an end portion of the space portion may slip out of the fastener tape. These troubles cause faulty products.
Accordingly, the present invention has been achieved to solve the above-described problems, and therefore, an object of the invention is to provide a woven slide fastener stringer, wherein a pitch between adjacent coupling element portions is stabilized and the warp yarns constituting a warp yarn pocket are woven in a high density so that excellent plasticity and flexibility are secured, attachment thereof to a material can be carried out by sewing at high speed and floating of binding warp yarns can be suppressed after a space portion is formed.
The above object is achieved effectively by the present invention.
According to the invention, there is provided a slide fastener stringer in which a plurality of coupling element portions continuously formed from synthetic resin monofilament are woven in a fastener tape comprising plural foundation weft yarns and warp yarns in succession along a side edge thereof, at the same time when the fastener tape is woven, with plural element binding warp yarns in parallel to each other. The coupling element portion comprises a coupling head protruded outward from a side edge of the fastener tape, upper and lower leg portion extending inward of the tape from both ends of the coupling head and a connecting portion for connecting each end of the upper and lower leg portion with upper and lower leg portions of adjacent coupling element portions. Among the plural element binding warp yarns running in parallel, at least two element binding warp yarns disposed on a side toward the coupling head run over an upper face of the upper and lower leg portions of each of the coupling element portions disposed in parallel along a longitudinal direction of the tape and then run under a foundation weft yarn running in parallel to a coupling element portion of a next position and the coupling element portion, each of the element binding warp yarns being woven in this repeating unit.
With such a structure, even when a desired number of the coupling element portions are cut out to form the space portion, because the binding warp yarn in the same cut out portion runs under the foundation weft yarn disposed under the lower leg portion of each coupling element portion and further runs over the foundation weft yarn disposed below the lower leg portion of an adjacent coupling element portion, each binding warp yarn never floats largely. Thus, no considerable trouble occurs in any subsequent manufacturing process of the slide fastener, thereby improving production efficiency.
Preferably, the repeating unit of at least two adjacent element binding warp yarns disposed on a side toward the coupling head is deviated by an amount corresponding to a single adjacent coupling element portion in the longitudinal direction of a tape. As a result, each coupling element portion is supported equally by the binding warp yarn so that the pitch between the coupling element portions is stabilized.
Further preferably, the foundation weft yarn is a two-folded yarn by double pick. By forming a single foundation weft yarn with two-folded yarn by double pick, even when the density of the weft yarn is reduced to xc2xd with respect to normal case, the function of the fastener tape is not lost, and further the production efficiency doubles.
Further preferably, the foundation weft yarn is a two-folded yarn lain-in by double picks and each coupling element portion is woven into the fastener tape each time when the foundation weft yarn is inserted by double pick. According to this, in addition to the operation of the above, the plasticity and flexibility of the fastener tape are secured although the weft yarn density is at necessary minimum. Thus, the slide fastener can be attached to flexible attachment material without losing the flexibility and be put along the attachment material at the time of sewing also.
Also preferably, a foundation warp yarn is disposed between the element binding warp yarn disposed nearest from the coupling head and the coupling head, and the foundation warp yarn runs alternately over and under adjacent weft yarns inserted by double picks alternately. The foundation weft yarn inserted by double pick is branched to back and forth directions at a tape end on a side of the coupling element row so as to form a tape end. Thus, usually, the branch end mingles with the binding warp yarn so as to form a tape end, the tape end is constructed by mingling with the foundation warp yarn according to the present invention. Further, in that mingling condition, the foundation warp yarns run over and under the adjacent foundation weft yarn by double picks, alternately so as to secure stabilization of the structure of the tape end. Further, no looseness is caused at the branch end of the foundation weft yarn even when the space portion is formed.